                    {:char "C" :addr 60 :bytes [0xF0 0x80 0x80 0x80 0xF0]}
                    {:char "D" :addr 65 :bytes [0xE0 0x90 0x90 0x90 0xE0]}
                    {:char "E" :addr 70 :bytes [0xF0 0x80 0xF0 0x80 0xF0]}
-                   {:char "F" :addr 75 :bytes [0xF0 0x80 0xF0 0x80 0x80]}]
-        m (:memory machine-state)]
+                   {:char "F" :addr 75 :bytes [0xF0 0x80 0xF0 0x80 0x80]}]]
     (reduce (fn [machine-state font]
               (reduce-kv (fn [machine-state byte-index byte-data]
                            (set-memory 


(defn get-memory
  [machine-state addr]
  (assert (< addr memory-size)) 
  (->byte (get (:memory machine-state) addr)))

(defn set-memory
  [machine-state addr value]
  (assert (< addr memory-size)) 
  (aset-short (:memory machine-state) addr (->byte value))
  machine-state)

(defn set-instr
  [machine-state addr value]


(defn- initialise-memory
  [machine-state]
  (assoc machine-state :memory (vec (repeat memory-size 0))))

(defn- initialise-stack
  [machine-state]
